It is known to use a rotary-type slicing machine to produce both waffle-cut and lattice-cut potato slices for preparation of french-fried potatoes or potato chips. Waffle-cut potato slices generally have alternating ridges and grooves on opposing faces, the grooves being relatively shallow compared to the thickness of the slices. Lattice-cut potato slices are similar, but the grooves on one face are transverse to those on an opposing face and are cut sufficiently deep as to intersect and produce a lattice-like appearance.
Rotary-type potato slicing machines for such purposes are described in U.S. Pat. Nos. 3,139,127 and 3,139,130 to Urschel et al. Such slicing machines comprise a central rotating carriage and a plurality of radial guides fixed to the carriage. Potatoes received by the central carriage are urged by centrifugal forces outwardly through the radial guides against stationary knife assemblies. These knife assemblies are typically mounted on a housing sidewall having a part-spherical shape and extend at preselected angles from the sidewall into the path of the orbiting potatoes. Thin slices are produced as each potato successively engages the various knife assemblies, each slice escaping tangentially through an opening in the housing sidewall located outwardly of an particular cutting blade.
The knife assemblies of the Urschel machine use thin corrugated blades to produce waffle and lattice cuts. In order to produce transverse networks of grooves on opposing faces of a potato slice, the radial guides and the potatoes contained therein are rotated synchronously with rotation of the carriage. The cut surface of each potato is essentially rotated through 90 degrees between successive engagements with a knife assembly. If the amplitude of the blade corrugations is sufficiently great relative to the thickness of the slices being cut then the resulting potato slices have a lattice-shape.
The original Urschel slicer is limited to producing lattice-cut slices having a thickness of no more than about 1/8 inch. Similar limitations arise in the depth of waffle-cuts which can be produced. This problem arises largely because of the construction and support of the blade. Each blade is essentially a thin sheet of metal appropriately bent to form longitudinal corrugations. Since the blade is relatively flexible, it is commonly supported by clamping its opposing faces rearwardly of its leading cutting edge. If the amplitude of the corrugations is sufficiently great to produce relatively thick lattice-cut slices, there is a tendency for an inner clamping member to shear ridges freshly-cut on a potato and for an outer clamping member to shear ridges freshly-cut on an escaping potato slice.
This shortcoming in the Urschel cutter is addressed in prior U.S. Pat. No. 4,523,503 to Julian et al. The Julian patent suggests that clamping members be formed with tapered fingers which extend forwardly into the grooves of an associated blade. As a potato and slice are advanced along the thin corrugated blade, they encounter the fingers and are raised clear of the clamping members. One significant shortcoming associated with such devices is that considerable debris tends to lodge between the blade, fingers and clamping member, which complicates cleaning of the rotary cutter. Similar blade clamp features are taught in prior U.S. Pat. No. 4,120,089 to Borner.
The present invention addresses the same problem, but seeks to modify the construction of the blade itself in a such a manner that the clamping members which might otherwise interfere with proper cutting of a potato slice are entirely eliminated.